There are a variety of crimping apparatuses known to the industry. Such crimping apparatuses range from relatively simple devices that are inexpensive to manufacture to complex, special purpose devices that are very expensive. Usually, the simpler devices employ an air cylinder as the source of power and a pair of pivoting jaws that are pivoted by extending or retracting the piston rod of the air cylinder. These angular motion crimping devices, while suitable for various general crimping operations, such as crimping hose ends onto fittings, are not always suitable for precision crimping operations such as those performed in the electrical cable and connector industries.
A well known crimping apparatus for general crimping operations is shown in FIGS. 1 and 2. The crimping apparatus, indicated as 10, includes an angular motion gripper 12, such as the style RG round body gripper manufactured by Compact Air Products, Inc., P.O. Box 439, 2424 Sandifer Blvd., Westminster S.C. 29693, and a suitable mounting bracket 14. The gripper 12 includes an air cylinder actuator 16 and a pair of jaws 18 which are pivotally attached to the frame of the actuator by the pins 20. Each jaw 18 includes a half round hole 22 in an edge so that the two half round holes are mutually opposed. The cylinder 16 has a piston rod 24 that extends outwardly and is coupled to the jaws 18 by means of a drive pin 26 that extends laterally through the piston rod and into the two opposing half round holes, as shown. When the piston rod 26 is retracted from its extended position, as shown in FIG. 1, the piston rod 24 moves toward the left causing the two jaws 18 to pivot about their respective pins 20 in the direction of the arrows 30 and 32 until they reach their closed position shown in FIG. 2. The jaws 18 include crimping dies 34 that are formed directly in their mating surfaces, however, the dies may be separate inserts that are screwed to the jaws. Note that, as the piston rod 24 begins to pivot the two jaws 18 from their open positions shown in FIG. 1, the direction of movement of the crimping dies 34 is about 30 degrees from the horizontal. That is, the dies have a vertical component moving them toward each other but they have a much larger horizontal component moving them to the left, as indicated by the arrows 36 in FIG. 1. As the piston rod 24 is extended, from the position shown in FIG. 2, the two jaws 18 pivot about their respective pins 20 in the direction of the arrows 38 and 40 until they reach their open position shown in FIG. 1. This horizontal component of motion results in the center of the crimping dies 34 being moved laterally a substantial distance between the open and closed positions. This can be undesirable when the item being crimped is held stationary by other mechanisms, such as in automated machinery where there are other work stations adjacent the crimping apparatus 10. Additionally, the horizontal component of movement of the two crimping dies 34 can adversely affect the quality of the crimp in certain applications such as when crimping a ferrule onto the shield conductor of a cable when terminating the end of the cable to an electrical connector. In such cases it is required that the two crimping dies 34 move along a substantially straight line toward each other and that the line of movement not move laterally any appreciable amount so that the cable is not damaged. The present invention provides a parallel motion apparatus for performing crimping and other manufacturing operations that meets these requirements.